According to the 2016 World Health Organization (WHO) classification of central nervous system (CNS) tumors, gliomas are classified from grade II to grade IV by not only histological characteristics but also several molecular pathological features, e.g., IDH (IDH1 and IDH2) mutation and chromosome 1p/19q co‐deletion status [6]. The gene discussed is IDH2; the disease is central nervous system cancer.